We are currently experiencing a couple more days of below freezing temps at night. This time we made sure to dump before hand so that we don't have to mess with it again until it warms up again. Totally agree with having respect for the tank valves in cold weather... and the sewer hose. Hubby was lucky that it was frozen solid at one point as he tore the sewer hose trying to thaw it! Luckily he was able to reattach before it let go!
lol